U.S. patent application number 13/104272 was filed with the patent office on 2011-11-17 for route retrieval apparatus and navigation apparatus.
This patent application is currently assigned to DENSO CORPORATION. Invention is credited to Masahiro MIYOSHI.
Application Number | 20110279255 13/104272 |
Document ID | / |
Family ID | 44911270 |
Filed Date | 2011-11-17 |
United States Patent
Application |
20110279255 |
Kind Code |
A1 |
MIYOSHI; Masahiro |
November 17, 2011 |
ROUTE RETRIEVAL APPARATUS AND NAVIGATION APPARATUS
Abstract
A route retrieval apparatus is disclosed. The route retrieval
apparatus includes a storage component, a first correction
component, a second correction component and a retrieval component.
The storage component stores therein probe information to specify
fuel consumption in each section, the probe information having been
collected from probe vehicles. The first correction component
corrects gradient information of each section based on the
specified fuel consumption in the each section. The second
correction component corrects a fuel cost of each section based on
the gradient information corrected by the first correction
component. The retrieval component retrieves, by using the fuel
cost of the each section corrected by the second correction
component, a route with a lowest total of the fuel costs from a
departure point to a destination point.
Inventors: |
MIYOSHI; Masahiro;
(Kuwana-city, JP) |
Assignee: |
DENSO CORPORATION
Kariya-city
JP
|
Family ID: |
44911270 |
Appl. No.: |
13/104272 |
Filed: |
May 10, 2011 |
Current U.S.
Class: |
340/441 ;
701/532 |
Current CPC
Class: |
G01C 21/3469
20130101 |
Class at
Publication: |
340/441 ;
701/200 |
International
Class: |
G01C 21/36 20060101
G01C021/36; B60Q 1/00 20060101 B60Q001/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 11, 2010 |
JP |
2010-109557 |
Claims
1. A route retrieval apparatus for calculating respective fuel
costs of sections of roads and retrieving a route with a lowest
total of the fuel costs from a departure point to a destination
point, the route retrieval apparatus comprising: a storage
component configured to store therein probe information to specify
fuel consumption in each section, the probe information having been
collected from runs of a plurality of probe vehicles; a first
correction component configured to correct gradient information of
each section based on the specified fuel consumption in the each
section, the specified fuel consumption being based on the probe
information, the gradient information being contained in map data
and indicating gradient of the each section; a second correction
component configured to correct a fuel cost of each section based
on the gradient information corrected by the first correction
component; and a retrieval component configured to retrieve, by
using the fuel cost of the each section corrected by the second
correction component, a route with a lowest total of the fuel costs
from a departure point to a destination point.
2. The route retrieval apparatus according to claim 1, wherein: the
first correction component is configured to correct the gradient
information of each section, so that as the fuel consumption
specified by the probe information is less efficient in the
section, the corrected gradient information causes the fuel cost of
the section to be less efficient.
3. The route retrieval apparatus according to claim 1, wherein: the
probe information is mean fuel consumption information, which
indicates an average of the fuel consumption of the plurality of
probe vehicles.
4. The route retrieval apparatus according to claim 1, further
comprising: a communication component configured to communicate
with an information center, the information center being configured
to collect the probe information from the plurality of probe
vehicles to specify the fuel consumption in each section, wherein:
the communication component is further configured to acquire the
probe information from the information center; and the acquired
probe information is stored in the storage component.
5. The route retrieval apparatus according to claim 1, wherein the
route retrieval apparatus is mounted to a subject vehicle, the
route retrieval apparatus further comprising: an information
collection component configured to collect driving characteristic
information to determine a driving characteristic of a driver of
the subject vehicle, wherein the driving characteristic influences
the fuel consumption of the subject vehicle; and a driving
characteristic classification component configured to determine and
classify the driving characteristic of the driver based on the
driving characteristic information collected by the information
collection component, wherein: the first correction component is
further configured to correct the gradient information further
based on the driving characteristic of the driver, so that as the
driving characteristic of the driver in the section is less
efficient in the fuel consumption, the corrected gradient
information causes the fuel cost of the section to be less
efficient.
6. The route retrieval apparatus according to claim 5, wherein: the
driving characteristic information, which is used to determine the
driving characteristic influencing the fuel consumption of the
subject vehicle, includes statistical information on acceleration
of the subject vehicle.
7. The route retrieval apparatus according to claim 5, wherein: the
information collection component is further configured to collect
the driving characteristic information while making a distinction
between the driving characteristic information at an up-hill
section and that at a down-hill section; the driving characteristic
classification component is further configured to determine and
classify the driver's driving characteristic influencing the fuel
consumption, while making a distinction between the driver's
driving characteristic when the subject vehicle is traveling on the
up-hill section and that when the subject vehicle is traveling on
the down-hill section; and the first correction component is
further configured to correct the gradient information while making
a distinction between the gradient information of the up-hill
section and that of the down-hill section.
8. A navigation apparatus mounted to a subject vehicle and
configured to carry out route guidance according to a guidance
route, the navigation apparatus comprising: a route retrieval
apparatus recited in claim 1, the route retrieval apparatus being
configured to retrieve the guidance route for the route guidance;
an accelerator pedal position acquisition component configured to
acquire accelerator pedal pressing information to specify an amount
of pressing down an accelerator pedal of the subject vehicle; and a
warning component configured to warn a driver of the subject
vehicle about an accelerator pedal operation in cases where the
amount of pressing down the accelerator pedal specified from the
accelerator pedal pressing information is determined to exceed a
accelerator pedal pressing threshold for the section where the
subject is located, wherein: the map data contains the accelerator
pedal pressing threshold on a section-by-section basis.
9. The route retrieval apparatus according to claim 1, wherein: the
route retrieval apparatus is mounted to an electric vehicle; the
fuel consumption is power consumption; and the fuel cost is a power
cost.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application is based on and claims priority to
Japanese Patent Application 2010-109557 filed on May 11, 2010,
disclosure of which is incorporated herein by reference.
BACKGROUND
[0002] 1. Technical Field
[0003] The present invention relates to a route retrieval apparatus
and a navigation apparatus that calculate a fuel cost of each
section (road section) based on road information contained in map
data, and that retrieve a route with a lowest total of the fuel
costs from a departure point and a destination point.
[0004] 2. Description of Related Art
[0005] A known route retrieval apparatus calculates a fuel cost of
each section based on road information contained in map data, and
retrieves a route with a lowest total of the fuel costs from a
departure point and a destination point. Such a route retrieval
apparatus may correct a fuel cost by using gradient (road gradient)
information of each section contained in the road information of
the map data (see paragraphs [0026] to [0027] of JP-H5-189698A1 for
example).
[0006] The inventor of the present application has found out the
followings.
[0007] Since the gradient information contained in the road
information is prescribed on a section-by-section basis (e.g., on a
link-by-link basis), one section inclined at a constant gradient
between both ends thereof and another section having up/down hills
between both ends thereof are the same in the gradient indicated by
the gradient information, as long the one section and the another
section have the same height difference between the both ends. As a
result, when the fuel cost is corrected by using the gradient
information, the one section and the another section are the same
in correction amount. However, in reality, when a vehicle travels
on roads, the fuel consumption is less efficient in a section
having up/down hills as compared with a wholly-flat section.
[0008] As can be seen from the above, the route retrieval apparatus
is configured to calculate the fuel cost of each section based on
the road information of the map data, correct the fuel cost of each
section based on the gradient information of the each section
contained in the road information, and retrieve a route with a
lowest total of the fuel costs from a departure point to a
destination point. In this configuration, since the route retrieval
apparatus does not take into account the up/down hills in the
course of a section, the route retrieval apparatus has low accuracy
in retrieving a route with a lowest total of fuel costs.
SUMMARY
[0009] In view of the foregoing, it is an objective of the present
disclosure to provide a route retrieval apparatus and a navigation
apparatus that can retrieve a route with a lowest total of fuel
costs with high accuracy.
[0010] According to a first aspect of the present disclosure, a
route retrieval apparatus is provided to calculate respective fuel
costs of sections of roads and retrieve a route with a lowest total
of the fuel costs from a departure point to a destination point.
The route retrieval apparatus includes a storage component, a first
correction component, a second correction component and a retrieval
component. The storage component is configured to store therein
probe information to specify fuel consumption in each section, the
probe information having been collected from runs of multiple probe
vehicles. The first correction component is configured to correct
gradient information of each section based on the specified fuel
consumption in the each section, the specified fuel consumption
being based on the probe information, the gradient information
being contained in map data and indicating gradient of the each
section. The second correction component is configured to correct a
fuel cost of each section based on the gradient information
corrected by the first correction component. The retrieval
component is configured to retrieve, by using the fuel cost of the
each section corrected by the second correction component, a route
with a lowest total of the fuel costs from a departure point to a
destination point.
[0011] According to the above route retrieval apparatus, the
gradient information of each section contained in the map data is
corrected based on the fuel consumption in the each section
specified based on the probe information. Based on the corrected
gradient information of each section, the fuel cost of each section
is corrected. By using the corrected fuel cost of each section, the
route with the lowest total of the fuel costs form the departure
point to the destination point is retrieved. Thus, even when one
section and another section are the same in height between two end
of the section, the gradient information of such sections can be
corrected based on the fuel consumption in the sections specified
by the probe information, so that the one section and the another
section are different in gradient. As a result, a route with a
lowest total of the fuel costs can be retrieved with high
accuracy.
[0012] According to a second aspect of the present disclosure, a
navigation apparatus mounted to a subject vehicle and configured to
carry out route guidance according to a guidance route is provided.
The navigation apparatus includes the above-described route
retrieval apparatus configured to retrieve the guidance route for
the route guidance Further, the navigation apparatus includes: an
accelerator pedal position acquisition component configured to
acquire accelerator pedal pressing information to specify an amount
of pressing down an accelerator pedal of the subject vehicle; and a
warning component configured to warn a driver of the subject
vehicle about an accelerator pedal operation in cases where the
amount of pressing down the accelerator pedal specified from the
accelerator pedal pressing information is determined to exceed a
accelerator pedal pressing threshold for the section where the
subject is located. The map data contains the accelerator pedal
pressing threshold on a section-by-section basis.
[0013] According to the above navigation apparatus, when the amount
of pressing down the accelerator pedal specified from the
accelerator pedal pressing information is determined to exceed the
accelerator pedal pressing threshold for the section where the
subject is located, the driver of the subject vehicle is warned
about his or her accelerator pedal operation. Therefore, it is
possible to further reduce the fuel cost.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The above and other objects, features and advantages
relating to the present invention will become more apparent from
the following detailed description made with reference to the
accompanying drawings. In the drawings:
[0015] FIG. 1 is a block diagram illustrating a navigation
apparatus according a first embodiment;
[0016] FIG. 2 is a flow chart illustrating a process for correcting
gradient information of each section based on probe information and
correcting a fuel cost of each section by using the corrected probe
information;
[0017] FIG. 3 is a diagram for explanation on a correction map;
[0018] FIG. 4 is a diagram illustrating a relation among gradient
information, probe information and corrected gradient
information;
[0019] FIG. 5 is a flowchart illustrating a process for warning a
driver about his or her accelerator pedal operation;
[0020] FIG. 6 is a flowchart illustrating a process for classifying
driver's driving characteristic based on acceleration of a
vehicle;
[0021] FIG. 7 is a diagram illustrating a relation between
acceleration distribution and driving characteristic; and
[0022] FIG. 8 is a diagram for explanation on a
fuel-consumption-influencing-gradient index, which indicating an
influence of gradient on fuel consumption.
DETAILED DESCRIPTION OF EMBODIMENTS
[0023] Embodiments will be described with reference to the
accompanying drawings.
First Embodiment
[0024] FIG. 1 illustrates a navigation apparatus 1 of a first
embodiment. The navigation apparatus 1 functions as a route
retrieval apparatus.
[0025] The navigation apparatus 1 is mounted a vehicle (called
herein "subject vehicle") and includes a position locating device
10, a map data input device 11, an in-vehicle LAN interface 12, a
communication device 13, a display device 14, a speaker 15 and a
controller 16.
[0026] The position locating device 10 includes a GPS (global
positioning system) receiver 10a, a vehicle speed sensor 10b, a
gyroscope 10c and a geomagnetic sensor 10d, each of which outputs
information for identification of present position of the vehicle.
The position locating device 10 inputs the information for
identification of the present position of the vehicle to the
controller 16.
[0027] The map data input device 11 inputs map data, which is used
for map display and route retrieval and which is stored in a
non-volatile storage medium, to the controller 16. In response to a
request from the controller 16, the map data input device 11 reads
out a requested piece of map data from the non-volatile storage
medium.
[0028] The map data includes a road data, a facility data, a
background data and the like. The road data has information about
link position, information about link type, information about road
class of link indicating whether the link corresponds to toll road,
general road, narrow street or the like, gradient information of
sections indicating gradient of the section on a section-by-section
basis (e.g., a link-by-link basis), information about node
position, information about node type, information about a
connection relation between nodes and links, and the like. The
facility data has multiple records for each facility. The multiple
records respectively correspond to name information indicating name
of the facility, positional information indicating position of the
facility, facility type information indicating type of the
facility, and the like. The background data has information about
position, shape and name of rivers, lakes, oceans, railway and
facility, and the like.
[0029] The in-vehicle LAN interface 12 acts as an interface for
connection to the in-vehicle LAN. Various ECUs such as an engine
ECU (electronic control unit), a body ECU, a door ECU and the like
are connected with the in-vehicle LAN.
[0030] The communication device 13 communicates with an outside of
the navigation apparatus 1 via a wireless communication network
(not shown). For example, the communication device 13 may perform
telephone communication, data transmission or the like. In the
present embodiment, the communication device 13 is communicatable
with an information center 2 via the wireless communication
network.
[0031] The display device 14 includes a display screen such as a
liquid crystal display and the like. On the display screen, the
display device 14 displays an image according to an image signal
inputted from the controller 16. The speaker 15 outputs a sound
(e.g., speech) according to a sound signal (e.g., speech signal)
inputted from the controller 16.
[0032] The controller 16 is configured as a computer having a CPU
(central processing unit), a RAM (random access memory), a ROM
(read-only memory), a storage device, and an I/O (input/output) and
the like. The controller 16 performs various processes using the
CPU according to programs stored in the ROM.
[0033] The processes of the controller 16 include a present
position identification process, a map display process, a
destination retrieval process, a route retrieval process, a travel
guidance process, and the like. The present position identification
process is performed to identify the present position based on the
information that the position locating device 10 inputs as a basis
for identifying the present position. The map display process is
performed to display, for example, such a map display screen that a
vehicle position mark is superimposed on a map around the present
position of the vehicle. The destination retrieval process is
performed to retrieve a destination point according to user
manipulation. The route retrieval process is performed to retrieve
a guidance route from a departure point (e.g., the present
position) to the destination point. The travel guidance process is
performed to carry out travel guidance according to the guidance
route.
[0034] In the present embodiment, in the route retrieval process,
at least one retrieval condition is selectable from multiple
retrieval conditions such as a toll road priority, a general road
priority, a time priority, a distance priority, a fuel consumption
priority and the like. The toll road priority gives the priority to
travel on a toll road. The general road priority gives the priority
to travel on a general road (non-toll road). The time priority
gives the priority to a route with a minimum travel time from a
departure point to a destination point. The distance priority gives
the priority to a route with a minimum distance from a departure
point to a destination. The fuel consumption priority gives the
priority to a route with a minimum fuel cost from a departure point
to a destination point.
[0035] The information center 2 includes a server for performing
various computation operations. With the server, the information
center 2 implements a service of providing traffic information,
e.g., traffic jam information, construction work information,
regulation information, and the like. The information center 2
further implements the following service. From a lot of specific
probe vehicles (e.g., taxies etc.), the information center 2
receives probe information including a variety of data that is
collected from runs of the multiple probe vehicles. Based on the
received data, the information center 2 makes a database and
provides a service of distributing information in the database in
response to a request from a vehicle. In the present embodiment,
the information center 2 receives information on fuel consumption
in each section from the multiple probe vehicles, stores mean fuel
consumption information of section in the database, and distributes
the mean fuel consumption information of each section to a vehicle
in response to a request from the vehicle. In the above, the mean
fuel consumption information indicates an average of the fuel
consumption of the multiple probe vehicles in each section and is
obtained as the sum of the fuel consumption of the multiple probe
vehicle divided by the number of probe vehicles.
[0036] In response to user operation (e.g., a command from a user),
the controller 16 connects the communication device 13 to the
information center 2, acquires the probe information from the
information center 2 and records the acquired probe information in
the storage medium. In the above, the probe information is
information that has been collected from the runs of the probe
vehicles to specify fuel consumption in each section. In the
present embodiment, the probe information is the mean fuel
consumption information described on a section-by-section
basis.
[0037] In the present embodiment, when the controller 16 retrieves
a route with a lowest total of the fuel costs from a departure
point to a destination point, the controller 16 corrects the fuel
cost of each section by not merely using the gradient information.
Specifically, when the controller 16 retrieves a route with a
lowest total of the fuel costs from a departure point to a
destination point, the controller 16 performs a process to correct
the gradient information based on the probe information stored in
the storage device, and correct the fuel cost of each section by
using the gradient information that has been corrected based on the
probe information.
[0038] The above process is more specifically illustrated in the
flowchart of FIG. 2. When an ignition switch of the vehicle is put
in an on state in response to user manipulation, the navigation
apparatus 1 is put in an operating state. When a departure point
and a destination point are specified in response to user
manipulation, and when the navigation apparatus 1 is instructed to
perform route retrieval using the fuel consumption priority as the
retrieval condition in response to user manipulation, the
controller 16 performs the process illustrated in FIG. 2.
[0039] At S100, from the map data input device 11, the controller
16 reads out the road data of a region covering the departure point
and the destination point. Further, from the storage device, the
controller 16 reads out the probe information of the region
covering the departure point and the destination point. In the
above, the probe information indicates the mean fuel consumption
information on a section-by-section basis.
[0040] At S102, the controller 16 corrects the gradient information
of each section based on the probe information. Specifically, a
correction map used to correct the gradient information of each
section based on the probe information (e.g., the mean fuel
consumption information of each section) is stored in the ROM. By
using this correction map, the controller 16 corrects the gradient
information of each section based on the probe information.
[0041] Now, the correction map will be illustrated with reference
to FIGS. 3 and 4. As shown in FIG. 3, the correction map prescribes
a relation between the mean fuel consumption and
fuel-consumption-influencing-gradient index F, where the
fuel-consumption-influencing-gradient index F is an index
indicating an influence of road gradient on fuel consumption). The
relation is prescribed such that the
fuel-consumption-influencing-gradient index F is larger as the mean
fuel consumption is less efficient, and the
fuel-consumption-influencing-gradient index F is smaller as the
mean fuel consumption is more efficient.
[0042] The fuel-consumption-influencing-gradient index F1
corresponding to a mean fuel consumption A is larger than the
fuel-consumption-influencing-gradient index F2 corresponding to a
mean fuel consumption B. Further, the
fuel-consumption-influencing-gradient index F2 corresponding to the
mean fuel consumption B is larger than the
fuel-consumption-influencing-gradient index F3 corresponding to a
mean fuel consumption C.
[0043] In the present embodiment, the controller 16 corrects the
gradient information of each section by adding (i) the
fuel-consumption-influencing-gradient index F corresponding to the
mean fuel consumption of the section to (ii) the gradient
information of the section contained in the map data.
[0044] As shown in FIG. 4, when a first section corresponding to a
link "n-1" has the gradient information 1 (%) and the mean fuel
consumption A (cc/m), the controller 16 corrects the gradient
information of the first section by adding (i) the
fuel-consumption-influencing-gradient index F1 (%) corresponding to
the mean fuel consumption A (cc/m), to (ii) the gradient
information 1 (%). Accordingly, the corrected gradient information
of the first section corresponding to the link "n-1" is given as
1+F1 (%).
[0045] When a second section corresponding to a link "n" has the
gradient information 0.5 (%) and the mean fuel consumption B
(cc/m), the controller 16 corrects the gradient information of the
second section by adding (i) the
fuel-consumption-influencing-gradient index F2 (%) corresponding to
the mean fuel consumption B (cc/m) to (ii) the gradient information
0.5 (%). Accordingly, the corrected gradient information of the
second section corresponding to the link "n" is given as 0.5+F2
(%).
[0046] Likewise, when a third section corresponding to a link "n+1"
has the gradient information 0.3 (%) and the mean fuel consumption
C (cc/m), the controller 16 corrects the gradient information of
the third section by adding (i) the
fuel-consumption-influencing-gradient index F3 (%) corresponding to
the mean fuel consumption C (%) to the gradient information of 0.3
(%). Accordingly, the corrected gradient information of the third
section corresponding to the link "n+1" is given as 0.3+F3 (%).
[0047] As can be seen from the above, the gradient information of
each section is corrected so that as the fuel consumption in a
section specified by the probe information is less efficient, the
section is described as having a larger gradient. In other words,
the gradient information of each section is corrected so that as
the fuel consumption in the section specified by the probe
information is less efficient, the fuel cost of the section is less
efficient.
[0048] Now, explanation returns to FIG. 2. At S104, the controller
16 corrects the fuel cost of each section based on the corrected
gradient information. In the present embodiment, the controller 16
corrects the fuel cost of each section in such manner that the
controller 16 calculates an amount of the fuel consumption in each
of sections from the departure point to the destination point, and
corrects the calculated amount of the fuel consumption in the each
of sections by using the gradient information corrected at S102. As
for a technique for calculating an amount of the fuel consumption
in each link and making a correction on it using road gradient, see
JP-2009-79995A1 for example.
[0049] At S106, the controller 16 retrieves a guidance route (also
called herein "eco-route") with a lowest fuel cost. For example, a
route with a minimum total of the fuel consumption is specified as
the guidance route.
[0050] At S108, the controller 16 displays the guidance route
(eco-route) on the display screen of the display device 14, and the
process illustrated in FIG. 2 is ended.
[0051] The map data of the navigation apparatus 1 stores therein an
accelerator pedal pressing threshold on a section-by-section basis.
The controller 16 determines whether an amount of pressing an
accelerator pedal (also called gas pedal) of the subject vehicle
exceeds the accelerator pedal pressing threshold for a section
where the subject vehicle is located. Hereinafter, the amount of
pressing the accelerator pedal of the subject vehicle is
abbreviated as accelerator pedal pressing amount. When the
controller 16 determines that the accelerator pedal pressing amount
exceeds the accelerator pedal pressing threshold, the controller 16
performs a process for warning the driver about his or her
accelerator pedal operation.
[0052] FIG. 5 is a flowchart illustrating the process for warning
the driver about his or her accelerator pedal operation. When the
navigation apparatus 1 is put in the operating state, the
controller 16 starts performing the process illustrated in FIG.
5.
[0053] At S200, from the map data input device 11, the controller
16 acquires the information that is contained in the map data
around the position of the subject vehicle to specify the
accelerator pedal pressing threshold. Further, via the in-vehicle
LAN interface 12, the controller 16 acquires information for
specifying the actual accelerator pedal pressing amount. In the
present embodiment, the controller 16 acquires a throttle valve
opening as the information for specifying the actual accelerator
pedal pressing amount.
[0054] At S202, the controller 16 determines whether the actual
accelerator pedal pressing amount specified by the throttle valve
opening exceeds the accelerator pedal pressing threshold for the
section where the vehicle is presently located.
[0055] When the actual accelerator pedal pressing amount does not
exceed the accelerator pedal pressing threshold for the section
where the vehicle is presently located, the determination "NO" is
made at S202, and the process returns to S200.
[0056] When the actual accelerator pedal pressing amount exceeds
the accelerator pedal pressing threshold for the section where the
vehicle is presently located, the determination "YES" is made at
S202, the process proceeds to S204. At S204, the controller 16
warns the driver about his or her accelerator pedal operation. For
example, a message indicating "the accelerator pedal is pressed
down too much" is displayed by the display device 14 and outputted
as sound from the speaker 15.
[0057] According to the above configuration, the storage device
stores therein the probe information, which has been collected from
the runs of the multiple probe vehicles to specify the fuel
consumption in each section. Further, the gradient information of
each section contained in the map data is corrected based on the
fuel specified consumption in the each section, the specified
consumption being based on the probe information stored in the
storage device. Further, a fuel cost of each section is corrected
based on the corrected gradient information of the each section. By
using the corrected fuel cost of the each section, a route with a
lowest total of the fuel costs from a departure point to a
destination point is retrieved. Thus, for example, even when one
section and another section are the same in height between opposite
ends of the section, the gradient information of such sections are
corrected based on the fuel consumption in the sections specified
by the probe information, so that the one section and the another
section are different in gradient (gradient information). As a
result, a route with a lowest total of the fuel costs can be
retrieved with high accuracy.
[0058] Moreover, according to the above configuration, the
information center 2 collects the probe information from the
multiple probe vehicles, which collect the probe information while
traveling on sections of roads to specify the fuel consumption on a
section-by-section basis. The navigation apparatus 1 acquires the
probe information from the information center 2 and records the
acquired probe information in the storage device. Therefore, based
on the fuel consumption in each section identified from the latest
probe information, the gradient information of each section
contained in the map data can be corrected.
[0059] According to the above configuration, when it is determined
that the gas pedal pressing amount in the subject vehicle exceeds
the gas pedal pressing threshold for the section where the subject
vehicle is located, the driver is warned about his or her gas pedal
operation. Therefore, it is possible to further reduce fuel
cost.
Second Embodiment
[0060] A second embodiment will be illustrated. The second
embodiment and the first embodiment can be the same in construction
of the navigation apparatus 1 shown in FIG. 1. In the first
embodiment, the navigation apparatus 1 corrects the gradient
information by using the probe information, which specifies the
fuel consumption in each section. In the second embodiment, the
navigation apparatus 1 corrects the gradient information by further
performing the followings. The navigation apparatus 1 collects
driving characteristic information to determine driver's driving
characteristic influencing the fuel consumption of the subject
vehicle, and classifies the driver's driving characteristic.
According to this driver's driving characteristic, the gradient
information is further corrected. In should be noted that like
reference numerals are used to refer to like parts between
embodiments.
[0061] In the present embodiment, the controller 16 performs a
processes illustrated in FIG. 6 to perform the following. The
controller 16 collects acceleration of the subject vehicle as the
driving characteristic information, which is used to determine the
driver's driving characteristic influencing the fuel consumption of
the subject vehicle, and the controller 16 classifies the driver's
driving characteristic based on statistical information of the
collected acceleration.
[0062] FIG. 6 illustrates a flowchart of this process. When the
subject vehicle is traveling, the controller 16 cyclically performs
the process in FIG. 6 at predetermined intervals.
[0063] At S300, the controller 16 collects the acceleration of the
subject. In the present embodiment, based on a vehicle speed signal
inputted from the vehicle speed sensor 10b, the controller 16
collects the acceleration of the subject vehicle. The acceleration
can be obtained by dividing a vehicle speed difference (speed
change amount) by a collection time interval.
[0064] At S302, the controller 16 determines and classifies the
driver's driving characteristic and records the classified driver's
driving characteristic in the storage device. In the present
embodiment, the driver's driving characteristic is classified into
three categories, i.e., a sudden driving characteristic
corresponding to a sudden driving operation, a normal driving
characteristic corresponding to a normal driving operation, and a
loose driving characteristic corresponding to a loose driving
operation.
[0065] FIG. 7 illustrates a relation between acceleration
distribution and driving characteristic. As shown in FIG. 7, the
driver's driving characteristic can be classified according to the
acceleration distribution. Based on this relation shown in FIG. 7,
the controller 16 determines the driver's driving characteristic
that matches the acceleration distribution of the subject vehicle,
and the controller 16 records the identified driving characteristic
as the statistical information of the acceleration of the subject
vehicle in the storage device. In the above way, the driver's
driving characteristic is classified and recorded in the storage
device.
[0066] In the present embodiment, the controller 16 performs a
process similar to that shown in FIG. 2. In this regard, however,
after the controller 16 corrects the gradient information of each
section based on the probe information at S102, the controller 16
further corrects the gradient information according to the driver's
driving characteristic classified at S302.
[0067] In the present embodiment, a diving characteristic factor
for the loose driving characteristic, that for the normal driving
characteristic and that for sudden driving characteristic are
denoted by ".alpha.", ".beta." and ".gamma.", respectively. The
gradient information is corrected using the
fuel-consumption-influencing-gradient index F multiplied by the
diving characteristic factor that matches the driver's driving
characteristic. In the present embodiment, the diving
characteristic factors .alpha., .beta., .gamma. satisfy the
following: 0<.alpha.<.beta.<.gamma..
[0068] As shown in FIG. 8, as for the first section corresponding
to the link "n-1" with the gradient information 1 (%) and the
fuel-consumption-influencing-gradient index F1,
fuel-consumption-influencing-gradient information is calculated to
be the fuel-consumption-influencing-gradient index F1 multiplied by
one of the diving characteristic factors .alpha., .beta., .gamma.,
that matches the driver's driving characteristic. Accordingly, the
gradient information of the first section (link "n-1") is corrected
so that the corrected gradient information is given as
"1+F1.times..alpha. (%)", "1+F1.times..beta. (%)" or
"1+F1.times..gamma. (%)".
[0069] As for the second section corresponding to the link "n" with
the gradient information 0.5 (%) and the
fuel-consumption-influencing-gradient index F2, the
fuel-consumption-influencing-gradient information is calculated to
be the fuel-consumption-influencing-gradient index F2 multiplied by
one of the diving characteristic factors .alpha., .beta., .gamma.,
that matches the driver's driving characteristic. Accordingly, the
gradient information of the second section (link "n") is corrected
so that the corrected gradient information is given as
"0.5+F2.times..alpha. (%)", "0.5+F2.times..beta. (%)" or
"0.5+F2.times..gamma. (%)".
[0070] As for the third section corresponding to the link "n+1"
with the gradient information 0.3 (%) and the
fuel-consumption-influencing-gradient index F3, the
fuel-consumption-influencing-gradient information is calculated to
be the fuel-consumption-influencing-gradient index F3 multiplied by
one of the diving characteristic factors .alpha., .beta., .gamma.,
that matches the driver's driving characteristic. Therefore, the
gradient information of the third section (link "n+1") is corrected
so that the corrected gradient information is "0.5+F2.times..alpha.
(%)", "0.5+F2.times..beta. (%)" or "0.5+F2.times..gamma. (%)".
[0071] In this way, the gradient information is corrected so that
as the driving characteristic of the driver in a section is less
efficient in the fuel consumption, the fuel cost of the section is
less efficient.
[0072] According to the above configuration, the driving
characteristic information, which is used to determine the driver's
driving characteristic influencing the fuel consumption of the
subject vehicle, is collected. Based on the collected driving
characteristic information, the driver's driving characteristic of
the subject vehicle is determined and classified. The gradient
information is corrected, so that as the driving characteristic of
the driver in a section is less efficient in the fuel consumption,
the corrected gradient information causes the fuel cost of the
section to be less efficient. Accordingly, the corrected gradient
information of each section reflects the driver's driving
characteristic in the section that may have a positive or negative
influence on the fuel cost. Therefore, a route with a lowest total
of fuel costs can be retrieved with higher accuracy.
Third Embodiment
[0073] A third embodiment will be illustrated. In the second
embodiment, the driver's driving characteristic is classified
according to the acceleration distribution of the subject vehicle.
However, for example, depending on whether the subject vehicle is
traveling on an up-hill or a down-hill, the driver's driving
characteristic may change. The driver classified as the loose
driving characteristic may not always have the loose driving
characteristic in the up-hill section (or the down-hill).
[0074] A third embodiment is made in view of the foregoing. In the
third embodiment, the controller 16 determines whether the subject
is traveling on an up-hill or a down-hill, based on the signal
inputted from the gyroscope 10c. The controller 16 collects the
driving characteristic information (which is used to determine the
driver's driving characteristic) while making a distinction between
(i) the driving characteristic information used to determine the
driver's driving characteristic at the up-hill and (ii) that at the
down-hill. The controller 16 classifies the driver's driving
characteristic while making a distinction between the driver's
driving characteristic at the up-hill and that at the
down-hill.
[0075] For example, the driver's driving characteristic in the
up-hill section may be classified as the sudden driving
characteristic in the following cases etc. A first case is that the
gas pedal pressing amount is larger than a predetermined threshold
or the acceleration is larger than a predetermined threshold when
the subject vehicle is traveling on the up-hill. A second case is
that, although the map data and the present position of the subject
indicate that the subject vehicle is approaching an end of the
up-hill, the acceleration is larger than a predetermined
threshold.
[0076] The driver's driving characteristic in the up-hill section
may be classified as the loose driving characteristic in the
following case etc. The gas pedal pressing amount is smaller than a
predetermined threshold when the subject vehicle is traveling on
the up-hill.
[0077] The driver's driving characteristic in the down-hill section
may be classified as the sudden driving characteristic in the
following case etc. The gas pedal pressing amount is larger than a
predetermined threshold when the subject vehicle is traveling on
the down-hill.
[0078] The driver's driving characteristic in the down-hill section
may be classified as the loose driving characteristic in the
following case etc. Frequency of fuel injection stop caused by the
use of engine brake (e.g., low gear) is larger than a predetermined
threshold.
[0079] As can be seen from the above, although the driver's driving
characteristic may vary between the up-hill section and the
down-hill section, the controller 16 of the present embodiment
classifies the driving characteristic influencing the fuel
consumption of the subject vehicle while making a distinction
between when the subject vehicle is traveling on the up-hill
section and when the subject vehicle is traveling on the down-hill
section. Then, the controller 16 further corrects the gradient
information while making a distinction between the gradient
information of the up-hill section and that of the down-hill
section. Therefore, it becomes possible to correct the gradient
information in a manner suited to the driver's driving
characteristics at the up-hill and the down-hill.
Other Embodiments
[0080] In the above-described embodiments, the navigation apparatus
1 uses an amount of the fuel consumption in each section to
calculate a fuel cost of the each section, and retrieves a guidance
route with a lowest total of the fuel costs. When the navigation
apparatus 1 is mounted to, for example, an electric vehicle (EV)
using a motor as a travel power source, the navigation apparatus 1
may uses an electric power consumption amount of the motor in each
section to calculate a fuel cost of the each section, and retrieves
a guidance route with a lowest total of the fuel costs.
[0081] In the first embodiment, from the information center 2, the
navigation apparatus 1 acquires mean fuel consumption information
of each section as the probe information for specifying the fuel
consumption in the each section and corrects the gradient
information by using the acquired probe information. When the
navigation apparatus 1 is mounted to, for example, the electric
vehicle (EV), the probe information may be used to specify a mean
electric power consumption amount of the motor in each section, and
the gradient information may be corrected by using this probe
information. That is, in the case of the electric vehicle, the fuel
consumption is power consumption. The fuel cost is a power
cost.
[0082] In the second embodiment, the navigation apparatus 1
collects the driving characteristic information (e.g.,
acceleration), which is used to determine the driver's driving
characteristic having an influence on the fuel consumption of the
subject vehicle. Based on the collected driving characteristic
information, the navigation apparatus 1 determines and classifies
the driving characteristic of the driver of the subject vehicle.
The navigation apparatus 1 corrects the gradient information so
that as the driving characteristic of the driver of the subject
vehicle in a section is less efficient in fuel consumption, the
gradient information of the section causes the fuel cost of the
section to be smaller (less efficient). In another embodiment, the
navigation apparatus 1 may transmit the driving characteristic
information, which is used to determine the driver's driving
characteristic, to the information center 2 via the communication
device 13 as well as the information used to specify the fuel
consumption amount in each section.
[0083] In the second embodiment, the navigation apparatus 1
collects the acceleration of the subject vehicle as the driving
characteristic information, which is used to determine the driver's
driving characteristic influencing the fuel consumption of the
subject vehicle. Alternatively, the navigation apparatus 1 may
collect gas pedal pressing amount, fuel injection amount or the
like as the driving characteristic information.
[0084] In the above embodiments, the navigation apparatus 1 is an
example of a route retrieval apparatus. The storage device of the
controller 16 is an example of a storage means or component. The
controller 16, which is configured to perform S102, is an example
of a first correction means or component. The controller 16, which
is configured to perform S104, is an example of a second correction
means or component. The controller 16, which is configured to
perform S106, is an example of a retrieval means or component. The
communication device 13 is an example of a communication means or
component. The controller 16, which is configured to perform S300,
is an example of an information collection means or component. The
controller 16, which is configured to perform S302, is an example
of a driving characteristic classification means or component. The
controller 16, which is configured to perform S200, is an example
of a gas pedal position information acquisition means or component.
The controller 16, which is configured to perform S202 and S204, is
an example of a warning means or component.
[0085] According to a first example of the present disclosure, a
route retrieval apparatus for calculating respective fuel costs of
sections of roads and retrieving a route with a lowest total of the
fuel costs from a departure point to a destination point may be
configured in the following way. The route retrieval apparatus
includes a storage component, a first correction component, a
second correction component and a retrieval component. The storage
component is configured to store therein probe information to
specify fuel consumption in each section, the probe information
having been collected from runs of multiple probe vehicles. The
first correction component is configured to correct gradient
information of each section based on the specified fuel consumption
in the each section, the specified fuel consumption being based on
the probe information, the gradient information being contained in
map data and indicating gradient of the each section. The second
correction component is configured to correct a fuel cost of each
section based on the gradient information corrected by the first
correction component. The retrieval component is configured to
retrieve, by using the fuel cost of the each section corrected by
the second correction component, a route with a lowest total of the
fuel costs from a departure point to a destination point.
[0086] According to the above route retrieval apparatus, the
gradient information of each section contained in the map data is
corrected based on the fuel consumption in the each section
specified based on the probe information. Based on the corrected
gradient information of each section, the fuel cost of each section
is corrected. By using the corrected fuel cost of each section, the
route with the lowest total of the fuel costs form the departure
point to the destination point is retrieved. Thus, even when one
section and another section are the same in height between two end
of the section, the gradient information of such sections can be
corrected based on the fuel consumption in the sections specified
by the probe information, so that the one section and the another
section are different in gradient. As a result, a route with a
lowest total of the fuel costs can be retrieved with high
accuracy.
[0087] The above retrieval apparatus may be configured as follow.
The first correction component is configured to correct the
gradient information of each section, so that as the fuel
consumption specified by the probe information is less efficient in
the section, the corrected gradient information causes the fuel
cost of the section to be less efficient.
[0088] The above retrieval apparatus may be configured as follow.
The probe information is mean fuel consumption information, which
indicates an average of the fuel consumption of the multiple probe
vehicles.
[0089] The above retrieval apparatus may further include a
communication component configured to communicate with an
information center, the information center being configured to
collect the probe information from the multiple probe vehicles to
specify the fuel consumption in each section. In addition, the
communication component may be further configured to acquire the
probe information from the information center. The acquired probe
information may be stored in the storage component.
[0090] According to the above configuration, the probe information
acquired from the information center, which collects the probe
information from the multiple probe vehicles to specify the fuel
consumption on a section-by-section basis, is recorded and stored.
Therefore, the gradient information of each section contained in
the map data can be corrected based on the fuel consumption in each
section identified from the latest probe information.
[0091] The above route retrieval apparatus may mounted to a subject
vehicle and may further include: an information collection
component configured to collect driving characteristic information
to determine a driving characteristic of a driver of the subject
vehicle, which influences the fuel consumption of the subject
vehicle; and a driving characteristic classification component
configured to determine and classify the driving characteristic of
the driver based on the driving characteristic information
collected by the information collection component. The first
correction component may be further configured to correct the
gradient information further based on the driving characteristic of
the driver, so that as the driving characteristic of the driver in
the section is less efficient in the fuel consumption, the
corrected gradient information causes the fuel cost of the section
to be less efficient.
[0092] According the above configuration, the gradient information
can corrected so that as the driving characteristic of the driver
in a section is less efficient in the fuel consumption, the
corrected gradient information causes the fuel cost of the section
to be less efficient. Therefore, a route with a lowest total of the
fuel costs can be retrieved with higher accuracy.
[0093] The above retrieval apparatus may be configured such that
the driving characteristic information, which is used to determine
the driving characteristic influencing the fuel consumption of the
subject vehicle, includes statistical information on acceleration
of the subject vehicle.
[0094] The above retrieval apparatus may be configured in the
following way. The information collection component is further
configured to collect the driving characteristic information while
making a distinction between the driving characteristic information
at an up-hill section and that at a down-hill section. The driving
characteristic classification component is further configured to
determine and classify the driver's driving characteristic
influencing the fuel consumption, while making a distinction
between the driver's driving characteristic when the subject
vehicle is traveling on the up-hill section and that when the
subject vehicle is traveling on the down-hill section. The first
correction component is further configured to correct the gradient
information while making a distinction between the gradient
information of the up-hill section and that of the down-hill
section.
[0095] The driver's driving characteristic may vary between the
up-hill section and the down-hill section. According to the above
configuration, however, it is possible to correct the gradient
information in a manner suited to the driver's driving
characteristic at the up-hill and that at the down-hill.
[0096] According to a second example of the present disclosure, a
navigation apparatus mounted to a subject vehicle and configured to
carry out route guidance according to a guidance route may be
configured in the following way. The navigation apparatus includes
the above-described route retrieval apparatus configured to
retrieve the guidance route for the route guidance Further, the
navigation apparatus includes: an accelerator pedal position
acquisition component configured to acquire accelerator pedal
pressing information to specify an amount of pressing down an
accelerator pedal of the subject vehicle; and a warning component
configured to warn a driver of the subject vehicle about an
accelerator pedal operation in cases where the amount of pressing
down the accelerator pedal specified from the accelerator pedal
pressing information is determined to exceed a accelerator pedal
pressing threshold for the section where the subject is located.
The map data contains the accelerator pedal pressing threshold on a
section-by-section basis.
[0097] According to the above navigation apparatus, when the amount
of pressing down the accelerator pedal specified from the
accelerator pedal pressing information is determined to exceed the
accelerator pedal pressing threshold for the section where the
subject is located, the driver of the subject vehicle is warned
about his or her accelerator pedal operation. Therefore, it is
possible to further reduce the fuel cost.
[0098] Additional advantages and modifications will readily occur
to those skilled in the art. The invention in its broader terms is
therefore not limited to the specific details, representative
apparatus, and illustrative examples shown and described.
* * * * *